debian/control: Fix compiler build-dependencies for cross-building

gcc cross-compilers *do* now have Multi-Arch: foreign, so we have
to take the :native qualfiication off again.

(cherry picked from commit 84e53d21c3)

Closes: #863907

debian/changelog

@@ -411,6 +411,8 @@ linux (4.9.30-1) UNRELEASED; urgency=medium
   * SUNRPC: Refactor svc_set_num_threads()
   * NFSv4: Fix callback server shutdown (CVE-2017-9059) (Closes: #862357)
   * uapi: fix linux/if.h userspace compilation errors (see #822393, #824442)
+  * debian/control: Fix compiler build-dependencies for cross-building
+    (Closes: #863907)
 
   [ Salvatore Bonaccorso ]
   * tracing: Use strlcpy() instead of strcpy() in __trace_find_cmdline()

debian/config/defines

@@ -106,7 +106,7 @@ initramfs-generators: initramfs-tools initramfs-fallback
 
 [relations]
 # compilers
-gcc-6: gcc-6 <!stage1 !cross>, gcc-6-@gnu-type-package@:native <!stage1 cross>
+gcc-6: gcc-6 <!stage1 !cross>, gcc-6-@gnu-type-package@ <!stage1 cross>
 
 # initramfs-generators
 initramfs-fallback: linux-initramfs-tool

debian/config/hppa/defines

@@ -24,5 +24,5 @@ hardware: multiprocessor 64-bit PA-RISC
 hardware-long: HP PA-RISC 64-bit SMP systems with support for more than 4 GB RAM
 
 [relations]
-gcc-6: gcc-6 <!stage1 !cross>, binutils-hppa64-linux-gnu <!stage1 !cross>, gcc-6-hppa64-linux-gnu <!stage1 !cross>, gcc-6-hppa-linux-gnu:native <!stage1 cross>, binutils-hppa64-linux-gnu:native <!stage1 cross>, gcc-6-hppa64-linux-gnu:native <!stage1 cross>
+gcc-6: gcc-6 <!stage1 !cross>, binutils-hppa64-linux-gnu <!stage1 !cross>, gcc-6-hppa64-linux-gnu <!stage1 !cross>, gcc-6-hppa-linux-gnu <!stage1 cross>, binutils-hppa64-linux-gnu <!stage1 cross>, gcc-6-hppa64-linux-gnu <!stage1 cross>